Isotopes in tooth fossils add new clues to debate
The ancient kin of modern elephants may have spent much of their time in lakes, rivers or swamps.
Creatures in the proboscidean genus Moeritherium have been known for more than a century, but scientists have never agreed about how the animals lived, says Alexander G.S.C. Liu, a paleontologist at the University of Oxford in England.
Liu and his team analyzed fossils from 37-million-year-old rocks southwest of Cairo. Other fossils from the same sediments include terrestrial animals along with sharks and marine fish. The shapes of Moeritherium skulls, placement of their eyes and other features hint that the 300-kilogram animals lived aquatic or semiaquatic lifestyles. However, he notes, the arrangement of bones in their inner ears doesn’t suggest that the creatures could have heard well underwater. They likely were not full-time swimmers.
Liu and his colleagues weighed in on the debate by analyzing the ratio of oxygen